<!DOCTYPE html>
<html lang="zh-Hans">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>提示框</title>
    <style>
      body {
        background: lightgrey;
      }
      /* 1.设置.box样式：宽500，高300，圆边框border-radius：8px，相对定位，top150，水平居中margin:0 auto */
      .box {
        width: 500px;
        height: 300px;
        background: white;
        border-radius: 8px;
        position: relative;
        margin: 0 auto;
        top: 150px;
      }
      .box-title {
        background: rgb(13, 115, 239);
        border-radius: 12px;
        height: 40px;
        line-height: 40px;
      }
      .box-title h3 {
        color: white;
        font-size: 18px;
        padding-left: 20px;
      }
      .box-title a {
        position: absolute;
        right: 20px;
        top: 0px;
        color: black;
        font-size: 24px;
        text-decoration: none;
      }
      .box-content {
        padding: 90px;
        text-align: center;
      }
      .box-button {
        text-align: right;
        padding-right: 20px;
      }
      .box-button input {
        width: 100px;
        height: 30px;
        border: none;
        border-radius: 5px;
        background: rgb(13, 115, 239);
        color: white;
        font-size: 16px;
        cursor: pointer;
      }
    </style>
  </head>
  <body>
    <!-- 1.提示框 -->
    <div class="box">
      <!-- 2.提示框标题 -->
      <div class="box-title">
        <h3>系统提示</h3>
        <a href="#">×</a>
      </div>
      <!-- 3.提示框内容 -->
      <div class="box-content">亲，确定这么做吗？</div>
      <hr />
      <!-- 4.提示框按钮 -->
      <div class="box-button">
        <input type="button" value="确定" />
        <input type="button" value="取消" />
      </div>
    </div>
  </body>
</html>
